Search Results (1,947)

This study presents an integrated approach to processing the heavy fraction of coal tar (HFCT) using oil shale (OS) from Shubarkol Komir JSC to simultaneously increase the yield of valuable hydrocarbon fractions and extract rare and dispersed trace elements. The lack of data on the effect of shale on the process and the kinetics of multi-component “tar + shale” systems limits the development of effective technologies. TG/DTG analysis was combined with the Friedman, Ozawa–Flynn–Wall, and Šesták–Berggren methods for the first time to evaluate the role of oil shale (OS). It was shown that the addition of 13% OS provides a sustained reduction in activation energy (~85–86 kJ/mol) and optimal conditions for hydrometallization. At 420 °C, an initial H₂ pressure of 4 MPa, and a reaction time of 60 min, the yield of light fractions reaches 62.6%, and the solid residue concentrates Ti, Mo, Ge, and other rare and dispersed elements reach up to 66,000 g/t in total. The possibility of extracting Ge using the Purolite C100 sorbent has also been confirmed. The novelty of the study lies in demonstrating the donor–catalytic effect of shale and the practical prospects of solid residue as a secondary mineral raw materials. Full article

The objective of this study was to investigate the adsorption of 11 azoles (tebuconazole, ketoconazole, econazole, miconazole, fluconazole, clotrimazole, climbazole, flutriafol, epoxiconazole, tiabendazole, and imazalil) on natural and waste-derived sorbents such as ceramsite, perlite, pumice, sawdust, coconut fibers, heavy oil fly ash (HOFA), activated carbon, and silica gel. The results of adsorption efficiency for most sorbents varied depending on the azole compounds and their concentration. The highest adsorption for all tested compounds was obtained for activated carbon and heavy oil fly ash, reaching about 100% in both tested concentrations (0.2 mg L⁻¹ and 0.02 mg L⁻¹). The HOFA material was characterized in terms of elemental analysis (CHNS), confirming the elemental contents of 52% C, 0.65% H, 0.4% N, and 2.3% S. The specific surface area of HOFA was 11.2 m² g⁻¹, and scanning electron microscopy (SEM) results showed the spherical yet porous nature of the particles. Furthermore, the calculated adsorption isotherms demonstrated that for most tested azoles, the Dubinin–Radushkevich (D-R) isotherm best fits the data, with R² = 0.93 or more, which is characteristic of porous carbon materials. The results highlight the significant potential of the tested HOFA sorbent for effectively removing azoles, as the tests performed showed that it was possible to remove these compounds with a concentration of up to 0.2 mg L⁻¹ within an hour. This is particularly important because HOFA is an easily accessible waste material. Furthermore, the adsorption of azoles will not increase the cost of HOFA disposal when using the standard procedures currently applied to this waste. Full article

Flooding from hurricanes creates damp indoor environments that support mold growth and microbial contamination, posing long-term health risks for occupants. This pilot study evaluated TMVOCs, microbial activity, and environmental conditions in 13 Hurricane Ian-affected residences across multiple flood-affected neighborhoods. Air samples were collected using sorbent tubes and analyzed by gas chromatography–mass spectrometry, while microbial activity on surfaces was assessed via ATP bioluminescence. Visible mold and dampness were documented with the CDC/NIOSH Dampness and Mold Assessment Tool, and environmental measurements included temperature, relative humidity, and surface as well as hidden moisture. Median (IQR) TMVOC concentrations were 12 (8) µg/m³, with 61% of homes exceeding the 10 µg/m³ benchmark set by previous researchers despite minimal visible contamination. Spearman’s correlation revealed significant negative relationships between odor and surface microbial activity (ρ = −0.569, p < 0.05), indicating that organic debris may play a more crucial role in microbial activity within the tested homes, and that odors might originate from hidden microbes instead of surface microbial growth. Our study emphasizes the necessity of utilizing both chemical (TMVOC) and biological (ATP) indicators to evaluate poor air quality caused by molds in flood-affected homes, serving as a supplement to routine visible mold assessments. Full article

Developing sustainable and high-performance sorbents for efficient CO₂ capture is essential for mitigating climate change and reducing industrial emissions. In this study, phosphorus-doped porous carbons (LPSP-T) were synthesized via a one-step activation–doping strategy using lotus petiole biomass as a precursor and sodium phytate as a dual-function activating and phosphorus-doping agent. The simultaneous activation and phosphorus incorporation at various temperatures (650–850 °C) under a nitrogen atmosphere produced carbons with tailored textural properties and surface functionalities. Among them, LPSP-700 exhibited the highest specific surface area (525 m²/g) and a hierarchical porous structure, with abundant narrow micropores (<1 nm) and phosphorus-containing surface groups that synergistically enhanced CO₂ capture performance. The introduction of P functionalities not only improved the surface polarity and binding affinity toward CO₂ but also promoted the formation of a well-connected pore network. As a result, LPSP-700 delivered a CO₂ uptake of 2.51 mmol/g at 25 °C and 1 bar (3.34 mmol/g at 0 °C), along with a high CO₂/N₂ selectivity, fast CO₂ adsorption kinetics and moderate isosteric heat of adsorption (Q_st). Furthermore, the dynamic CO₂ adsorption capacity (0.81 mmol/g) was validated by breakthrough experiments, and cyclic adsorption–desorption tests revealed excellent stability with negligible loss in performance over five cycles. Correlation analysis revealed pores < 2.02 nm as the dominant contributors to CO₂ uptake. Overall, this work highlights sodium phytate as an effective dual-role agent for simultaneous activation and phosphorus doping and validates LPSP-700 as a sustainable and high-performance sorbent for CO₂ capture under post-combustion conditions. Full article

Mercury poses serious hazards to human health. Carbon nanotube (CNT) is a potential material for elemental mercury (Hg⁰) adsorption removal, however, it shows susceptibility to SO₂ and H₂O. Herein, CNT is first decorated with Fe₂O₃ then modified with MnCl₂ (MnCl₂-Fe₂O₃@CNT) to enhance SO₂ and H₂O resistance. The Hg⁰ removal performance and physical–chemical properties of samples are comprehensively studied. MnCl₂(10)FeCNT (10 wt% MnCl₂ content) has a high specific surface area (775.76 m²·g⁻¹) and abundant active chlorine (35.01% Cl* content) as well as oxygen species (84.23% O_α content), which endows it with excellent Hg⁰ adsorption capacity (25.06 mg·g⁻¹) and good SO₂ and H₂O resistance. Additionally, the superparamagnetic property can enable MnCl₂(10)FeCNT to be conveniently recycled. After fifth regeneration, MnCl₂(10)FeCNT can still achieve >90% Hg⁰ removal. The abundant active chlorine and oxygen species over MnCl₂(10)FeCNT are responsible for Hg⁰ removal with HgCl₂ as the primary product. This work demonstrates the enhancement of CNT’s resistance to SO₂ and H₂O by Fe₂O₃ and MnCl₂ modification, which has potential application in flue gas mercury removal. Full article

The removal of nickel from industrial wastewater necessitates efficient sorbent materials. This study investigates nanostructured potassium- and sodium-substituted aluminosilicate-based nanocomposites for this application. Materials were synthesized and characterized using SEM-EDS, XPS, XRD, FTIR, low temperature N₂ adsorption–desorption and Ni²⁺ adsorption experiments. SEM and XRD confirmed an X-ray amorphous structure attributable to fine crystallite size. The sodium-substituted material Na₂Al₂Si₂O₈ exhibited the lowest specific surface area (48.3 m²/g) among the tested composites. However, it demonstrated the highest Ni(II) sorption capacity (64.6 mg/g, 1.1 mmol/g) and the most favorable sorption kinetics, as indicated by a Morris-Weber coefficient of 0.067 ± 0.008 mmol/(g·min¹/²). Potassium-substituted analogs with higher Si/Al ratios showed increased surface area but reduced capacity. Analysis by XPS and SEM-EDS established that Ni(II) uptake occurs through a complex mechanism, involving ion exchange, surface complexation, and chemisorption resulting in the formation of new nickel-containing composite surface phases. The results indicate that optimal sorption performance for Ni(II) is achieved with sodium-based aluminosilicates at a low Si/Al ratio (Si/Al = 1). The functional characteristics of Na₂Al₂Si₂O₈ compare favorably with other silicate-based sorbents, suggesting its potential utility for wastewater treatment. Further investigation is needed to elucidate the precise local coordination environment of the adsorbed nickel. Full article

Mine effluents represent a serious environmental problem on a global scale. Therefore, the effective treatment of this water is a serious issue in the scientific field. The adsorption process seems to be one of the attractive methods, especially due to the simplicity of design, affordability or high efficiency. The latest scientific knowledge has shown that the use of waste and natural adsorbents is economical and effective. This study aimed to evaluate the efficiency of the adsorption process of natural and waste materials—zeolite, bentonite and fly ash—under the influence of temperature and modification of these adsorbents. The novelty of this study resides in an adjustment of the modification method of adsorbents compared to previous research: thermal–alkaline treatment versus hydrothermal one. Another novelty is the use of modified fly ash from biomass combustion as an adsorbent in comparison with the previously used fly ash from coal combustion. The modification of the adsorbents made the adsorption process more effective at all experimental concentrations. The characterisation of adsorbent samples was performed using X-ray diffraction (XRD). The parameters of the adsorption isotherms, Langmuir, Freundlich and Temkin, were estimated by nonlinear regression analysis. The adsorption capacity of Cu(II) of fly ash was comparable to natural adsorbents. Adsorption processes were better described by pseudo-second-order kinetics. At the end of this study, the suitability of using the adsorbents to reduce the concentration of Cu(II) in neutral mine effluents was observed in the following order at 30 °C: unmodified fly ash > modified bentonite > unmodified zeolite. At the temperatures of 20 °C and 10 °C, the same trend of the suitability of adsorbents use was confirmed: modified bentonite > modified zeolite > modified fly ash. The practical applicability of this study lies in the expansion of knowledge in the field of adsorption processes and in the improvement of waste management efficiency of heating plants not only in Slovakia, but also globally. Full article

Arsenic pollution in potable water is a significant worldwide health concern. This study systematically evaluates current progress in adsorption technology, the most promising restorative approach, to provide a definitive framework for future research and use. The methodology entailed a rigorous evaluation of 91 peer-reviewed studies (2012–2025), classifying adsorbents into three generations: (1) Natural adsorbents (e.g., agricultural/industrial wastes), characterized by cost-effectiveness but limited capacities (0.1–5 mg/g); (2) Engineered materials (e.g., metal oxides, activated alumina), which provide dependable performance (84–97% removal); and (3) Advanced hybrids (e.g., MOFs, polymer composites), demonstrating remarkable capacities (60–300 mg/g). The primary mechanisms of removal are confirmed to be surface complexation, electrostatic interactions, and redox precipitation. Nevertheless, the critical analysis indicates that despite significant laboratory efficacy, substantial obstacles to field implementation persist, including scalability limitations (approximately 15% of materials are evaluated beyond laboratory scale), stability concerns (e.g., structural collapse of MOFs at extreme pH levels), and elevated costs (e.g., MOFs priced at approximately $230/kg compared to $5/kg for alumina). The research indicates that the discipline must transition from only materials innovation to application science. Primary objectives include the development of economical hybrids (about $50/kg), the establishment of uniform WHO testing standards, and the implementation of AI-optimized systems. The primary objective is to attain sustainable solutions costing less than $0.10 per cubic meter that satisfy worldwide deployment standards via multidisciplinary cooperation. Full article

Waste materials have emerged as attractive low-cost feedstocks for adsorbent development in environmental remediation and materials engineering. Organic wastes are particularly rich in cellulose, hemicellulose, lignin, and pectin, which provide reactive oxygenated groups such as hydroxyls and carboxyls. While inorganic wastes offer stability, lower water retention makes them promising candidates. This study explores the functionalization of waste-derived organic and inorganic matrices using two amine-based agents: 3-aminopropyltrimethoxysilane (APTMS) and polyethylenimine (PEI). The materials were categorized as organic (orange peel, corn cob) or inorganic (silica gel, eggshell) and subjected to a pretreatment process involving drying, grinding, and sieving; inorganic substrates additionally underwent acid activation with citric acid. Surface modification was carried out in ethanolic (APTMS) or aqueous (PEI) media. To assess their suitability and processability as particulate sorbents, drying kinetics, physicochemical properties (FTIR, ζ-potential, pH, conductivity, Boehm titration), and flow characteristics (Carr and Hausner indices) were evaluated. The findings enable a comparative analysis of the functionalization efficiency and elucidate the relationship between substrate type (organic vs. inorganic) and its performance as a modified adsorbent. This approach advances the development of novel sorbent matrices for greenhouse gas mitigation while reinforcing circular economy principles through the valorization of low-cost, readily available waste materials. Full article

Sugar beet pulp (SBP) is a by-product from the sugar industry with low value. As a feed, SBP needs to be dried. However, the drying process takes too much energy, leading to potential environmental issues caused by coal use. This paper raised and tried a crosslinking method to shorten the drying process, save energy consumption, and increase the value of SBP. This paper aimed to reduce the water-holding ability of SBP while obtaining animal feed with higher nutritional value. First, the crosslinking method was used to evaluate its dryness–strengthening effect. Second, three factors were evaluated: operating temperature, solution pH, and cationic concentration. Third, a kinetic study was performed on the drying process of SBP through its crosslinking with macro-elements (Ca²⁺, Cu²⁺) using drying models; the characterization of Ca²⁺-SBP and Cu²⁺-SBP using FTIR, SEM, and XRD; and possible drying mechanisms, which were discussed using an egg box model and a simple quantum chemical calculation. Results showed that the dryness–strengthening and value-adding idea is more practical through a Ca²⁺-crosslinking method, rather than through crosslinking with Cu²⁺. Under experimental conditions, wet SBP with 2 g of dry base reacts to Ca²⁺ under optimized conditions of 1000 mg/L Ca²⁺ solution at pH 6.0 and 40 °C for 135 min, with a moisture content of 5.23 g/g as a water-holding index. Compared with SBP, the moisture content of the crosslinking SBP on a dry basis was reduced by ~30–40%. The Midilli–Kucuk model was the most suitable model to describe the hot-air drying process of SBP, while Ca²⁺ or Cu²⁺ can crosslink to the galacturonic acid in pectin and form an “egg-box” model. SBP binds with Ca²⁺ or Cu²⁺ through its carboxyl groups, as testified by a combination analysis of FTIR, SEM, and XRD. As a result, the SBP dried through the Ca²⁺-crosslinking or Cu²⁺-crosslinking method can be directly used as a feed additive with good economic benefit and without the post-treatment problem as a bio-sorbent. Full article

Herein, nanoscale MgAl₂O₄ (MOA), 10%CuO@MgAl₂O₄ (10Cu@MOA), 10%NiO@MgAl₂O₄ (10Ni@MOA), and 10%CoO@MgAl₂O₄ (10Co@MOA) were synthesized employing butylated hydroxytoluene (the food additive BHT) as a capping agent. The SEM images illustrated average sizes of 38.8, 30.0, 40.8, and 32.7 nm for MOA, 10Cu@MOA, 10Ni@MOA, and 10Co@MOA, respectively, and their BET surface area were 84.4, 141.8, 126.7, and 105.3, respectively. Doxycycline DXC removal was studied employing the MOA, 10Cu@MOA, 10Ni@MOA, and 10Co@MOA, which resulted in q_t values of 57.3, 106.1, 97.7, and 73.9 mg g⁻¹, respectively. The pseudo-second order model best described the DXC sorption onto MOA, 10Cu@MOA, 10Ni@MOA, and 10Co@MOA, and both film diffusion models influenced the DXC sorptions onto the sorbents. The DXC sorption onto the 10Cu@MOA fitted the Freundlich model. The thermodynamics implied endothermic-spontaneous DXC sorption onto the10Cu@MOA. The pH study exposed that the DXC removal by 10Cu@MOA was more effective in a mildly acidic medium (pH = 6.0). Furthermore, the 10Cu@MOA effectiveness in treating surface water contaminated by 5.0 and 10.0 mg L⁻¹ DXC was 99.9% and 98.1%, respectively, while it was 94.7% and 92.5% in treating the concentrations above in seawater, respectively. The reusability study showed a 10% reduction in the 10Cu@MOA’s removal efficiency at the fourth cycle, which is encouraging for real-life applications. Full article

In view of the increasing environmental pollution caused by bisphenol A (BPA), understanding its impact on the microbiological properties of soil, which play a key role in maintaining soil fertility and consequently ecosystem stability, is particularly important. Therefore, the aim of this study was to assess the sensitivity of the soil microbiome to this xenobiotic and to evaluate the potential of organic materials such as starch (St), grass compost (Co), and fermented bark (B) to restore the balance of soil cultivated with Zea mays. The negative effects of BPA on the abundance, diversity, and structure of bacterial and fungal communities in soil contaminated with 500 and 1000 mg kg⁻¹ d.m. of soil were confirmed. Changes in the phospholipid profile, including phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylglycerol (PG), and ergosterol (E), were also assessed. BPA applied at 1000 mg kg⁻¹ d.m. of soil inhibited the proliferation of organotrophic bacteria and actinomycetes, while stimulating fungal growth. This xenobiotic’s impact is also reflected by a decrease in PC and PG levels in soil under BPA pressure. Through amplification of the V3-V4 16S rRNA region (for bacteria) and the ITS1 region (for fungi), the dominant bacterial phylum Proteobacteria was identified, with genera including Cellulosimicrobium, Caulobacter, Rhodanobacter, Sphingomonas, Mucilaginibacter, and Pseudomonas. Among fungi, Ascomycota dominated, primarily represented by the genus Penicillium. Of all the organic materials tested for mitigating BPA’s negative effects, grass compost was identified as the most promising, not only restoring soil homeostasis but also enhancing the growth and development of Zea mays cultivated in BPA-contaminated soil. Full article

The galvanic industry requires considerable amounts of water and produces significant quantities of wastewater. Two types of wastewater are created in the processes of the galvanic application of metal coatings: used galvanic baths and wastewater generated while rinsing coated elements. The composition and amount of wastewater depend on the type of process, the plant’s operational system, and the quantity of water utilised to rinse the coated elements. In this article, the possibilities of using different techniques, such as chemical precipitation, coagulation and flocculation, ion exchange, adsorption, and membrane filtration, to remove heavy metals from galvanic wastewater were analysed and assessed. It was determined that the use of physicochemical methods (i.e., chemical precipitation, coagulation, and flocculation) to remove heavy metals has significant disadvantages, including operational costs connected with the purchase of chemical reagents and the emergence of metal complexes requiring management/utilisation. On the other hand, the processes of ion exchange and adsorption can be used only for wastewater characterised by a low heavy metal concentration, with organic matter preliminarily removed. In addition, waste polluted with heavy metals in the form of used regenerative baths and used sorbents is generated during these processes. In turn, the advanced techniques of membrane filtration allow for the removal of different types of organic pollutants and heavy metals. The processes of membrane wastewater treatment exhibit a range of advantages compared to traditional technologies, including the complete, environmentally friendly removal of permanent organic pollution, easy integration into conventional technologies, a limited amount of residue, a high level of separation, and a shorter process time. The efficiency of membrane wastewater treatment depends on many parameters, including, most of all, the composition, pH, and type of membrane, as well as process conditions. The possibility of using new types of membranes to remove heavy metals from spent galvanic baths was analysed, and the possibility of using the processes in wastewater treatment systems according to the circular economy model was assessed. The assessment of the efficiency of heavy metal removal in hybrid systems combining specific individual processes and the development of state-of-the-art material solutions to realise these processes may be an interesting direction of research in this field. Full article

Produced water, a typical byproduct of oil and gas extraction, is considered a significant environmental and health problem due to its heavy metals content. The objective of this study is to evaluate and compare the efficiency of seven low-cost, waste-derived adsorbents in removing Cr³⁺, Cu²⁺, Fe²⁺, Zn²⁺, and Pb²⁺ from simulated produced water. The sorbents include gypsum, neem leaves, mandarin peels, pistachio shells, date seed powder, date seed ash, and activated carbon from date seeds. Adsorption experiments were performed using 2.5 and 5 g/L of the adsorbent. SEM and EDX analyses were used to confirm morphological changes and metal deposition after adsorption. Results showed that date seed ash exhibited the highest efficiency (85–100% across all metals), followed by activated carbon (25–98%), with strong Fe and Cu removal but a lower Pb uptake. Neem leaves, mandarin peels, and date seed powder showed moderate efficiencies (30–97%), while gypsum and pistachio shells were the least effective (0–81%). Lignocellulosic peels also showed good results due to the abundance of –OH and –COOH functional groups. Gypsum performed poorly across most metals. Integrating these waste-based adsorbents into secondary or tertiary treatment stages is an economical and sustainable solution for oil wastewater treatment. The results revealed the potential for valorizing agro-industrial and construction waste for circular economic applications in heavy metal pollution control. Full article

Wastewater analysis plays a central role in monitoring patterns of drug use within specific populations. It provides objective and real-time estimates of consumption, with minimal ethical concerns. In the current European context, drugs of abuse continue to be detected in wastewater, with varying incidences across countries. Their monitoring enables the prioritisation of public health and legal interventions by healthcare professionals and drug monitoring agencies. Therefore, the development and implementation of efficient methodologies for monitoring drugs of abuse in wastewater samples is of critical importance. This systematic review aims to explore the use of miniaturised sample extraction techniques based on solid-phase microextraction for the determination of drugs of abuse in wastewater. In fact, the extraction procedure must be fast, effective, and selective in order to retain the analytes of interest. Miniaturised techniques have thus emerged as promising alternatives to conventional methods. Magnetic solid-phase extraction (MSPE) and molecularly imprinted polymers (MIPs) represent the most widely applied solid-phase microextraction techniques in recent years for the analysis of drugs of abuse in wastewater. Looking ahead, future perspectives include the development of eco-friendly workflows, automated and time-efficient techniques, increasingly selective sorbents, and robust analytical methods. Full article